The field of the present invention is securing devices such as latches.
When it is desired to secure a first element such as a (door) panel to a second element such as a frame, a common device for securing consists of a latch having a mating flange which rotates and locks in position against the frame, securing the panel in place. Such a device is illustrated in FIG. 8. A door 303 is to be secured against a frame 307. The edge 303a of the door 303 is secured against the door jam 307a of the mating flange or frame 307 by a latch 306 on the door 303. The latch 306 includes a handle 304 pivoting in a direction A about a pivot point 305a thereby rotating a latch arm 305 in a direction B away from the door frame 307 (to the position shown by the flange 305' in broken line) thereby allowing the door 303 to open in a direction C.
The contact point of the latch arm 305 is typically a screw or bolt 320 which also provides height adjustment. The bolt is positioned on the arm 305 and locked at the desired height with a locking nut 380, 381 on either side of the latch arm 305 so the bolt head 322 contacts the frame 307.
For most applications, the bolt and nut securing means is totally adequate. However, conditions with vibration between the two elements may render the typical bolting means inadequate.
One problem which occurs is where a door is being secured down to a thin panel or mating flange and the door (or the mating flange) is subject to vibration. As the door vibrates, it moves parallel to the mating flange rubbing the bolt head against the mating flange causing wear and possibly wearing through the mating flange itself. The rubbing may also cause wear on the latch arm at the bolt connection or other location. In addition, as the head of the bolt rubs against the mating flange, it typically wears a circular pattern into the mating flange. As this wear continues, preload is decreased thereby permitting additional movement between the two elements further increasing wear between the elements.
The wear difficulties are most noticeable in applications of high vibration and large securing preloads. It is therefore desireable to reduce this wear and avoid loss of preload.